Heterosis definition types of heterosis heterosis in. The words homozygous and heterozygous were al ready in general use in reference to mendelian paired genes, so that the. Despite its importance in maize production, we know surprisingly little about the genetic basis of heterosis. Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Heterosis is prevalent for multiple traits in diverse maize germplasm sherry a. The fundamental genetic and physiological causes of heterosis remain. Edwards heterosis is the foundation of modern maize breeding programs. Find words for heterosis in english in this spanishenglish dictionary. Quantitatively, heterosis is measured by the difference between the value obtained in generation ft and the mean value of the parents, being maximum in generation f. Heterosis can be defend as the superiority of f hybrid over both the parents in terms of yield and some other character. Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of.
Ppt heterosis powerpoint presentation free to download. Hybrid vigor, also known as heterosis, is the miraculous phenomenon by which intercrossing two varieties of plants produces more vigorous hybrid offspring with higher yields. Heterosis is a systemic property emerging from non. Genetic background, heterosis, and sex differences can all have profound effects on chiasma and recombination frequencies. In fact, the biological basis of heterosis is considered by some scientists to be inadequately defined. After maize hybrid was first utilized in field on a large scale in usa in 1930s, heterosis of other crops such as rice, sorghum, rape, and vegetable etc began to be. Examples of how to use heterosis in a sentence from the cambridge dictionary labs.
Heterosis is in our corpus but we dont have a definition yet. Superiority of dominant alleles over recessive alleles 3. Ppt heterosis powerpoint presentation free to view. Any opinions in the examples do not represent the opinion of the cambridge dictionary editors or of cambridge university press or its licensors. An offspring is heterotic if its traits are enhanced as a result of. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of its parents. The value of expected progeny differences or epds as a genetic tool of selection is widely accepted especially in the seedstock industry. Heterosis definition and meaning collins english dictionary. Heterosis definition of heterosis by medical dictionary. The figure of speech heterosis as used in the bible god is the author of language, and the ability to communicate by words is one thing that sets apart man from all other creatures. East 19081909 studied the effects of inbreeding and outbreeding. An understanding of heterosis in genetic terms had to await the rediscovery of mendels laws in 1900. Sandeep kumar bangarwa the term heterosis was first used by shull in 1914.
Heterosis is prevalent for multiple traits in diverse. Darwin 1876 also reported that inbreeding in plants results in deterioration of vigour and the crossing in hybrid vigour. Heterosis is due to masking of deleterious recessive alleles by dominant alleles 4. On the basis of his experiments beal 18771882 concluded that f 1 hybrids yield as much as 40 percent more of the parental varieties from subsequent studies on intervarietal crosses in maize, it was observed that some of the hybrids show heterosis. The explanation of heterosis offered by jones was so probable that it was generally. Hybrid vigor, or heterosis, is the increase in stature, biomass, and fertility that characterizes the progeny of crosses between diverse parents such that the f1 is superior to the better of the two parents. In the other words, is it possible that a key gene controlling strong heterosis in one plant species can be applied in some other plants for hybrid breeding e. Heterosis, hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. Heterosis definition, the increase in growth, size, fecundity, function, yield, or other characters in hybrids over those of the parents. Strictly speaking, the words dominance and overdominance only apply to monogenic traits. Clear explanations of natural written and spoken english. These examples are from the cambridge english corpus and from sources on the web. Learn how to pronounce heterosis and more about the heterosis word at. Various models have been posited to explain heterosis.
Heterosis is observed in almost every crop species studied, the application of this phenomenon for its commercial exploitation depends on the expression of the degree of heterosis. In plants, this is basically achieved by a greater proliferation of cells in some but not all tissues 2. As much as 100 % or greater midparent heterosis f1 mp, where mp is the mean of the parents and over 40 % highparent heterosis f1 hp, where hp is the higher parent value have been. Words with friends change definition of heterosis the word heterosis. Coined the word heterosis to describe the increased vigor observed from heterozygosity.
These example sentences show you how heterosis is used. Heterosis may be defined as the superiority of an f 1, hybrid over both its parents in terms of yield or some other character heterosis. Heterosis, or hybrid vigor, refers to the phenomenon that progeny of diverse inbred varieties exhibit greater biomass, speed of development, and fertility. Heterosis hybrid vigor is the unusual health, stature, or fitness of offspring produced from the mating of unrelated inbred strains or between closely related species. Exploring the molecular basis of heterosis for plant breeding. Heterosis definition of heterosis by merriamwebster.
His work led to the formulation of the modern heterosis concept. Heterosis, otherwise known as outbreeding enhancement, is the opposite of inbreeding depression and is sometimes referred to as hybrid vigor. In other words, plants with aabb genomic constitutions were more. Heterosis, or hybrid vigor, an unsolved puzzle and a. Pdf heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudooverdominance. Heterosis definition of heterosis by the free dictionary. This increased productivity or superiority over the parents is known as heterosis or hybrid vigor. Any opinions in the examples do not represent the opinion of the cambridge dictionary.
Heterosis can be defend as the superiority of f hybrid over both the. Heterosis definition is the marked vigor or capacity for growth often exhibited by crossbred animals or plants called also hybrid vigor. Hybrid vigor in plants and its relationship to insect pollination pdf. The chasm of unanswered questions regarding heterosis. Heterosis hybrid vigor and breed complementarity are the primary benefits realized from a properly planned crossbreeding program. In search of the molecular basis of heterosis plant cell.
Heterosis, also called hybrid vigour, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. The figure of speech heterosis as used in the bible. The proposal to use heterosis instead of heterozygosis can be explained in a manner closely paralleling the statements of johanksen in launching the word gene, as quoted above, for the word heterozygosis like the word pan gene is a double construction of which the first half represents the important significant concept. The proposal to use heterosis instead of heterozygosis can be explained in a manner closely paralleling the statements of johanksen in launching the word gene, as quoted above, for the word heterozygosis like the word pan gene. Hybrid vigor is the unusual health, stature, or fitness of offspring produced from the. He heterosis problem has a central position in present day. The word in the example sentence does not match the entry word. Storing heterosis and recombination loss another option is for interbeef to store not compute the heterosis and recombination loss calculated at the national level. The advantages of crossbreeding are well documented and can have a big impact on your net return.
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